| 摘要 |
PURPOSE:To relatively simply prepare a hot molded spring while certainly preventing decarburization, by a method wherein water glass is applied to the surface of a spring grade steel material and, after hot molding, shot peening is applied to the molded one. CONSTITUTION:Water glass is applied to the entire surface or the necessary surface part of a spring grade steel material and the coated steel material is thrown into a furnace to be heated to a hardening temp. Whereby, because water glass is cured to cover the surface of the steel material and blocked the same from the contact with the atmosphere, decarburization is inhibited. The greater part of the cured water glass is broken by large strain generated during molding to be peeled off while the remainder is perfectly removed by shot peening and, therefore, there is no possibility of deteriorating in painting or appearance. |
